亲权鉴定中性染色体STR基因座异常分型的研究

目的观察性染色体STR基因座异常分型的特点,探讨其与性染色体遗传疾病的关系。方法对3200例亲权鉴定案例中8356名个体,采用Chelex100法提取DNA,常染色体及性染色体STR基因座复合扩增,荧光检测分型,对性染色体STR基因座的异常分型现象进行研究,并结合外周血细胞染色体核型分析结果对性染色体遗传疾病进行诊断。结果两个个体的牙釉蛋白(Amelogenin)性别基因座中X等位基因与Y等位基因的峰高比为2:1,结合性染色体STR基因座分型结果以及染色体核型分析,分别诊断为Turner综合征和Klinefelter综合征。结论性染色体STR基因座检测对性染色体遗传疾病的筛查方面具有一定应用价值。     

同一染色体中罕见三个短串联重复序列基因座突变分析

目的总结1例罕见的STR基因座突变。方法应用多位点复合PCR扩增技术及毛细管电泳分型技术,对亲子鉴定案例进行分析。结果 STR基因座D2S1338、TPOX和D2S441同时发生遗传突变且D2S1338基因座发生两步突变。结论亲子鉴定过程中,若只有1个或2个STR基因座违反孟德尔遗传规律时,若为单亲鉴定则需加测孩子生母STR基因座分型,若为双亲鉴定应增加遗传标记位点个数,综合分析以排除或认定亲子关系。     

中国人群中15个短串联重复序列位点的突变研究

目的对亲子鉴定中常用的PlowerPlex16(R)系统的15个短关重复序列(short tandem repeat, STR)位点的突变现象进行研究.方法在1921例确定亲权的案例中,对PlowerPlex16(R)系统的15个STR位点的突变现象进行了分析.结果在1921例确定亲权的案例中有70例(3.644%)观察到了突变,其中1例是两个位点同时突变(D21S11 and PentaD)、1例是2个子代不同位点发生突变(D7S820 and D16S539).在3764次减数分裂中,15个STR位点共观察到有72例突变,突变率为0.128%±1.104×10-3.vWA 和D21S11的突变率最高(0.292%),TH01和TPOX位点没有发现突变.父源突变是母源突变的5倍.大多数(98.611%)突变的等位基因为一步突变,一个重复单位的增加突变与减少突变之比为1.8261.只发现1例多步突变,表现为PentaD位点的等位基因的增加2个重复单位.在PlowerPlex16(R)系统中,D8S1179、Penta D、D13S317、D16S539、D7S820、D5S818、D3S1358、TH01和 TPOX 9个位点突变率低,更适用于亲权鉴定.结论 STR位点的突变是一个较为常见的现象,常使亲子鉴定中亲权认定变得更加复杂,因此筛选突变率低的稳定STR位点对于亲子鉴定非常重要.     

亲子鉴定中两个STR基因座多步突变分析

目的探讨母女二联体亲子鉴定中STR出现矛盾基因座的原因。方法被鉴定人样本DNA用AGCU EX22荧光检测试剂盒和21+1STR荧光检测试剂盒、STRtyper-10G试剂盒对46个常染色体STR基因座进行检测,并用AGCU X19-STR荧光检测试剂盒检测19个X染色体STR基因座。结果 EX22检测体系中发现D8S1179存在两步突变,21+1体系中发现D3S4529存在三步突变,其他STR基因座检测结果均符合遗传规律。结论亲子鉴定案例中出现的D8S1179和D3S4529基因座不符合属罕见的母源性两位点多步突变。     

中国人群Amelogenin基因的突变频率和突变类型

目的调查Amelogenin基因在中国人群的突变频率和突变类型,评估其对性别鉴定的影响。方法采用PowerPlex○R16系统对8850名已知性别的中国无关个体进行Amelogenin基因内含子1区6bp缺失的检测,统计分型异常的个体,采用Amelogenin基因其它引物体系和Y染色体短串联重复序列(Yshort tandem repeats,Y-STR)基因座对突变样本进行验证并测序。结果在男性群体中检出2例X染色体Amelo-genin(AMELX)等位基因丢失的样本和2例Y染色体Amelogenin(AMELY)等位基因丢失的样本,总突变率为0.045%,男性群体中的突变率为0.085%。对丢失的AMELX等位基因测序,在其正向引物结合区检出2种点突变,推测因此产生无效等位基因,该类突变在男性群体中约为0.042%;AMELY等位基因丢失在男性群体中的突变率也为0.042%,其中1个样本在12个Y-STR基因座中有10个基因座扩增失败,推测在Y染色体上包括AMELY和Y-STR基因座在内的较大片段缺失。结论Amelogenin基因突变会造成AMELX等位基因或AMELY等位基因丢失,将干扰性别鉴定,导致性别错判,在检验时值得注意。     

两种试剂中D6S474和D5S2500基因座等位基因分型一致性研究

目的观察分析两种STR基因座检测试剂盒中共有基因座D6S474和D5S2500的等位基因分型结果的差异。方法采用Chelex法对20名无关个体的血样提取DNA,并结合DNA参考物质9947A,分别采用Investigator HDplex试剂盒和AGCU21+1试剂盒,经PCR复合扩增STR基因座,毛细管电泳分离扩增产物和激光扫描片段分析,比较两种试剂中共有STR基因座D6S474和D5S2500等位基因分型的差异。结果 HDplex试剂中D6S474基因座等位基因分型与AGCU 21+1试剂中该基因座分型相比均减少一个重复序列;而两种试剂中D5S2500基因座的等位基因分型具有显著差异。结论不同厂商对同一个STR基因座的引物设计上存在差异,导致该基因座等位基因分型结果存在差异。实验室在应用多套STR基因座检测试剂盒检测时,应关注共有基因座分型结果的一致性。     

广西黑衣壮族D2S1338,D8S1179,D18S51基因座遗传多态性

目的 获得广西黑衣壮族人群3个STR基因座的群体遗传分布资料.方法 应用荧光标记STR基因扫描技术对152名广西黑衣壮族无关个体进行基因分型.结果 D2S1338检测出11种等位基因,频率分布在0.0030～0.2800.D8S1179检测出7种等位基因,频率分布在0.0987～0.2237.D18S51检测出12种等位基因,频率分布在0.0033～0.2467.对上述3个STR基因座的基因型观察值和期望值进行X^2检验,均符合Hardy-Weinberg平衡定律（P＞0.05）.D2S1338、D8S1179、D18S51基因多样性分别为0.8498、0.8450、0.8507;多态信息总量均为0.8300.结论 广西黑衣壮族3个STR基因座属高度多态性位点;D2S1338的等位基因19、D8S1179的等位基因10和D18S51的等位基因15可能是广西黑衣壮族群体中相应STR基因座最原始的等位基因.     

亲子鉴定中短串联重复序列基因座两步突变分析

目的 探讨亲子鉴定中短串联重复序列(short tandem repeat,STR)基因座突变产生的原因.方法 提取血样本基因组DNA,通过IdentifilerTM 和STRtyper荧光标记试剂盒对24个STR基因座进行检测,并加测6个人类Y染色体上的微小片段STR基因座.结果 IdentifilerTM检测系统中发现D18S51存在两步突变,其他基因座检测结果符合遗传规律.结论 本亲子鉴定案例中D18S51基因座分型结果符合STR突变的规律,属罕见的两步突变.     

云南藏族四个短串联重复序列基因座的基因频率

目的：了解云南藏族D21S11、D8S1179、D16S539和LPL4个短串联重复序列基因座的基因频率。方法：采用4个STR基因座引物在同一反应体系中互不干扰的复合扩增、变性聚丙烯酰胺凝胶电泳及银染法显色技术，对105名云南藏族个体4个STR基因座进行了基因频率调查。结果：观察到D21S11基因座的13个等位基因和33个基因型；D8S1179基因座的8个等位基因和21个基因型；D16S539基因座的7个等位基因和16个基因型；LPL基因座的6个等位基因和9个基因型。结论：4个基因座的基因型分布均符合Hardy-Weinberg平衡定律，且在藏族群体中有较好的多态性分布，适用于法医个体识别和亲权鉴定、遗传学及人类学的相关研究。     

山东汉族群体15个常染色体短串联重复序列的遗传多态性分析

目的 获取15个短串联重复序列(short tandem repeat,STR)基因座在山东汉族群体的群体遗传学数据.方法 应用AmpFISTR IdentifilerTM Kit试剂盒对15个SIR进行分型.结果 15个基因座的观察杂合度为0.605～0.882,期望杂合度为0.625～0.862,多态信息量为0.57～0.85,个体识别力为0.795～0.958,非父排除率为0.297～0.758.TPOX的等位基因频率,山东汉族群体与河南、吉林、江苏汉族群体间的非差异P值大于0.05;D13S317的等位基因频率,山东汉族群体与鄂温克族群体的P值大于0.05.结论 15个STR基因座在该群体多态性,除TPOX和TH01,其余13个STR基因座在山东汉族群体的非父排除率和累计个人识别机率较高.     

Evaluation of genetic parameters of 23 autosomal STR loci in a Southern Chinese Han population

Aim: To evaluate the 23 autosomal short tandem repeat (STR) loci included in GoldenEye? 25?A kit using forensic human identification and paternity testing.

Subjects and methods: In total, 3751 unrelated individuals from the Southern Chinese Han population were genotyped with the 5-dye GoldenEye? 25?A multiplex amplification system. PCR products were separated using arrayed capillary electrophoresis. Allele frequencies and forensic parameters for the 23 autosomal STR loci were statistically analysed.

Results: A total of 344 alleles were observed, with corresponding allelic frequencies ranging from 0.0001–0.5519 for the 23 STR loci. No significant deviation from the Hardy-Weinberg equilibrium and linkage disequilibrium was observed. The combined power of discrimination (CPD) was 1–1.6290?×?10^?28 and the combined power of exclusion (CPE) was 0.999 999 999 89 and 0.999 999 286 93 for trio and duo cases, respectively. From 3865 meioses, 87 mutation events were discovered. The mutation rate varied from 0–0.00285 for each locus. One-step mutation accounted for 94.25% of total mutations. The ratio of paternal vs maternal mutation was 3.76:1.13 kinds of n/(n?+?1) heterozygote genotypes were observed.

Conclusions: The results show that 23 STR loci of GoldenEye? 25?A kit are highly polymorphic in the Southern Chinese Han population, indicating the kit is suitable for forensic application.     

云南汉族15 个短串联重复序列基因座遗传多态性特征及分析

目的:调查云南地区汉族的D8S1179、D21S11、D7S820、CSF1PO、D3S1358、TH01、D13S317、D16S539、D2S1338、D19S433、VWA、TPOX、D18S51、D5S818、FGA 15 个短串联重复序列(Short tandem repeat,STR)基因座的遗传多态性。方法:收集云南汉族313 名无关个体血样,提取DNA,PCR 复合扩增并利用ABI鄄3130 型基因分析仪进行毛细管电泳检测每个样本各基因座的等位基因大小,分别统计每个STR 基因座各基因型的频率,并进行Hardy-Weinberg 遗传平衡检验。结果:云南汉族这15 个STR 基因座各基因型频率分布符合Hardy-Weinberg 平衡(P>0.05),杂合度在0.636 ~0.901,匹配概率在0.034 ~0.220,单一STR 位点的个体识别率在0.780 ~0.966、非父排除率在0.336 ~0.797、多态性信息总量在0.555 ~0.860,联合使用这15个位点所产生的累积个体识别率大于0.999 999 99,累积非父排除率等于0.999 998 408。与中国其他地区汉族群体这15 个STR 基因座等位基因频率分布相比有较高的相似性,但也有轻微的地区差异。结论:云南汉族的D8S1179、D21S11、D7S820、CSF1PO、D3S1358、TH01、D13S317、D16S539、D2S1338、D19S433、VWA、TPOX、D18S51、D5S818、FGA 这15 个STR 基因座具有高度的多态性,与中国其他地区汉族群体有较高的相似性,在法医学中的亲子鉴定和个人识别方面具有较高应用价值。     

九个非DNA联合索引系统短串联重复序列基因座在河北汉族群体的遗传学调查及在亲子鉴定中的应用

目的 调查9个非DNA联合索引系统(DNA combined index system,CODIS)的短串联重复序列(short tandem repeat,STR)基因座在河北汉族人群的等位基因分布,评估其在亲子鉴定中的应用价值.方法 应用 STRtyper 10G试剂盒调查147名河北汉族健康无关个体基因分型,计算...     

五核苷酸重复序列D6S957的等位基因序列结构及其群体遗传学

目的分析五核苷酸短串联重复序列(shorttandemrepeat,STR)D6S957每一个等位基因的DNA序列,以了解它们在人类基因组中的结构,并构建等位基因分型标准物,后者对于法医DNA分型是必须的.对德国群体和中国汉族群体D6S957进行调查,以了解D6S957基因型分布和等位基因频率.方法用扩增片段长度多态性对德国群体和中国汉族群体共计230份样本的D6S957基因型分布和等位基因频率进行了分析,等位基因的确定通过与自制的人类等位基因标准物比较完成.对每一等位基因进行了序列分析.结果D6S957STR呈现极少的影子带,使解释分型结果变得容易.总共在这些群体中发现有8个等位基因,基因型分布符合Hardy-Weinberg平衡.在64个已确定的家系中未观察到突变事件,用最大似然率法间接估计该基因座突变率为2.5×10-5.结论D6S957对于法医学个人识别与亲子鉴定是一个有用的遗传标记.     

Y-chromosomal microsatellite mutation rates: differences in mutation rate between and within loci

Precise estimates of mutation rates at Y-chromosomal microsatellite STR (short tandem repeat) loci make an important basis for paternity diagnostics and dating of Y chromosome lineage origins. There are indications of considerable locus mutation rate variability between (inter-) and within (intra-) loci. We have studied nine Y-STR loci-DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385, and DYS388-in 1,766 father-son pairs of confirmed paternity (a total of 15,894 meioses). Five biallelic markers were also analyzed in the fathers-Tat, YAP, 12f2, SRY1532, and 92R7-defining haplogroups 1, 2, 3, 4, 9, and 16, respectively. A total of 36 fragment length mutations were observed: 24 gains (22 single-step, two double-step) and 12 single-step losses. Thus, there was a significant surplus of gains (p=0.045). Overall, the mutation rate was positively correlated to STR repeat length and there was a significant relative excess of losses in long alleles and gains in short alleles (p=0.043). In contrast to the situation in autosomal STR loci and in MSY-1, no noteworthy correlation between mutation rate and the father's age at the child's birth was observed. We observed significant interlocus differences in Y-STR mutation rates (p<0.01). The number of observed mutations ranged from zero in DYS392 to eight in DYS391 and DYS390. We have also demonstrated obvious differences in mutation rates between the haplogroups studied (p=0.024), a phenomenon that is a reflection of the dependence of mutation rate on allele size. Our study has thus demonstrated the necessity of not only locus-specific, but even allele-specific, mutation rate estimates for forensic and population genetic purposes, and provides a considerable basis for such estimates.     

Mutation rate at commonly used forensic STR loci: paternity testing experience

Paternity tests are carried out by the analysis of hypervariable short tandem repeat DNA loci. These microsatellite sequences mutate at a higher rate than that of bulk DNA. The occurrence of germline mutations at STR loci posses problems in interpretation of resulting genetic profiles. We recently analyzed 59-159 parent/child allele transfers at 13 microsatellite loci. We identified 12 mutations in 7 microsatellite loci. No mutations were occurred in other 6 loci. The highest mutation rate was observed with 5 mutations at D8S1179 locus at different alleles. The event was always single repeat related. The mutation rate was between 0 and 1.5 x 10(-2) per locus per gamete per generation. The mutation event is very crucial for forensic DNA testing and accumulation of STR mutation data is extremely important for genetic profile interpretation.     

Variation in mutation rate and direction between tetranucleotide STR loci in human colorectal carcinomas

Replication error (RER) is defined as mutation events in repetitive DNA segments. To investigate further the RER phenomenon and reveal any differences in mutation outcome between different short tandem repeat (STR) loci, we have investigated the somatic mutation rate and the size distribution of new tumour alleles in four tetranucleotide STRs in a large material of unselected colorectal adenocarcinomas. DNA was extracted from the blood and carcinomas of 217 patients. All blood/tumour pairs were analysed using the STRs HUMTHO1, HUMFES/FPS, HUMVWA31/A and HUMF13A1. Mutations are detected at all four loci. There are substantial differences in mutation rate and mutation direction (i.e. expansion versus contraction) between different STR loci. In all four STRs, the majority of events represent gain or loss of a single repeat. Almost all new tumour alleles correspond to known alleles in a population database, indicating that these are also composed of integers of the four base pair repeat. There is no statistically significant size bias in the mutating alleles as compared to the allelic distribution in the population database.     

三个短串联重复序列位点的等位基因遗传变异研究

目的 探讨短串联重复序列（short tandem repeats,STRs）遗传变异的方式及机理。方法 用银染方法对3个STR位点（FGA、D12S391、D11S554)共19个发生突变的家系父、母、子的DNA样本进行SRT基因分型，将需测序的等位基因条带从凝胶上切下，再进行PCR扩增，产物经纯化作为测序模板，采用循环测序法测序。结果 19个家系中有18个家系子代新产生的等位基因变异表现为一个重复单位的增加或减少（表现为一个重复单位增加的有8个家系，减少的有7个家系，不确定的有3个家系），只有1个家系表现为2个重复单位的减少，子代新产生的等位基因来自父亲的有13个家系，来自母亲的有3个家系，不能确定的有3个家系，来自父与母的比较约为4：1。3个STR位点等位基因突变都出现在长的、连续的四核苷酸重复区（FGA的“CTTT”区、D12S391的“AGAT”区、D11S554的“AAAG”区）。结论 FGA、D12S391和D11S5543个STR位点的等位基因突变主要表现为一个重复单位的增加或减少占95％，其次是两个重复单位的变化，没有碱基的插入或缺失，突变主要来自父亲，在这3个STR位点中的长的、连续的四核苷酸重复区可能是等位基因突变的敏感点。     

九个非DNA联合索引系统核心短串联重复序列基因座在广东汉族人群的遗传多态性

目的 调查D7S3048等9个非DNA联合索引系统(combined of DNA index system,CODIS)指定的核心短串联重复序列(short tandem repeat,STR)基因座在广东汉族人群的遗传多态性.方法 采用荧光标记复合扩增和毛细管电泳技术,对广东汉族500名无关个体的DNA进行9个STR基因座分型.结果 500名无关个体在D7S3048等9个非CODIS核心STR基因座共检出115个等位基因,160种基因型,各基因座杂合度为0.824～0.884,个人识别能力为0.925～0.969,多态信息总量为0.77～0.86,均符合Hardy-Weinberg平衡(P>0.05),9个STR基因座的累计个体识别力达1.00×10~(-13),三联体累计非父排除率为0.999989488,二联体累计非父排除率为0.873436.结论 D7S3048等9个STR基因座在个体识别及亲子鉴定中是一个高效的检测系统,在二联体亲子鉴定中可作为补充基因座满足疑难、单亲和突变案件的需求.